Elsewhere in the volatile region, security forces killed 70 suspected militants in an area close to two major Taliban tribal strongholds, intelligence officials told The Associated Press.

No one immediately claimed responsibility for Tuesday's attack on the Peshawar Pearl Continental, but the blast followed Taliban threats to carry out major attacks in large cities to avenge an army offensive against insurgents in the nearby Swat Valley.

At least three suicide attackers shot their way past guards and set off the explosion late Tuesday outside the hotel, a favorite spot for foreigners and well-off Pakistanis and a site that the U.S. was considering for its consulate.

The attack reduced a section of the hotel to concrete rubble and twisted steel and left a huge crater in a parking lot. Senior police official Safwat Ghayur said counterterrorism experts, police and intelligence agents were combing the rubble for clues Wednesday.

The Pearl Continental, affectionately called the "PC" by Pakistanis, is the ritziest hotel in the rugged frontier city of 2.2 million. Relatively well-guarded and set back from the main road, it is near government buildings and overlooks a golf course and a historic fort.

Citing witness accounts, police said three men in a pickup truck approached the hotel's main gate, opened fire at security guards, rushed inside and detonated the bomb close to the building. The truck was carrying more than half a ton of explosives, senior police officer Shafqatullah Malik estimated.

The chaotic scene echoed a bombing last year at Islamabad's Marriott Hotel that killed more than 50 people. Both hotels were favored places for foreigners and elite Pakistanis to stay and socialize, making them high-profile targets for militants despite tight security.

In Washington, two senior U.S. officials said the State Department had been in negotiations with the hotel's owners to either purchase or sign a long-term lease for the facility to house a new American consulate in Peshawar. The officials said they were not aware of any sign that U.S. interest in the compound had played a role in its being targeted.

The officials spoke on condition of anonymity because the negotiations were not public and had not been completed. They said no immediate decision had been made on whether to go ahead with plans to base the consulate on the hotel grounds.

A member of the family that owns the Peshawar hotel and the Marriott in Islamabad said he was not aware of any negotiations with the U.S. but that the Pearl Continental would be rebuilt.

"The process has already started," Murtaza Hashwani said. "They have started clearing the debris, and the engineering people are looking at the building. You cannot let these people defeat you."

The exact death toll remained elusive Wednesday.

North West Frontier Province Information Minister Mian Iftikhar Hussain told The Associated Press early Wednesday that officials reported 11 fatalities. Other police and government officials could confirm only five dead.

The three attackers also died, said an intelligence official who spoke on condition of anonymity because he was not authorized to speak to the media. U.N. spokeswoman Amena Kamaal said three bodies pulled out of the rubble Wednesday belonged to two Pakistani government staffers whose work was funded by the U.N.'s population agency, along with their driver.

The U.N. also identified staff members among the dead.

One was Aleksandar Vorkapic, 44, from Belgrade, Serbia, who was part of a team sent by the world body to help with a massive refugee crisis. Also killed was UNICEF staffer Perseveranda So, 52, from the Philippines, who was working on educational programs for girls, the children's agency said.

Peshawar district coordination officer Sahibzada Anis said the blast wounded three others working for the U.N. agency -- a Briton, a Somali and a German.

U.N. officials declined to comment Wednesday on whether they might scale back their programs in Pakistan. Such a move could have significant consequences because of a refugee crisis sparked by the military offensive in Swat.

More than 2 million people have been displaced by fighting in the valley. Many are staying in sweltering relief camps.

On Tuesday, the Pakistani military took action in another nearby region, Bannu, after tribal elders there failed to move against militants in their midst who allegedly helped kidnap more than 100 students from a boys' school who were later freed.

Two intelligence officials said troops, backed by helicopter gunships and artillery, attacked the Jani Khel section of Bannu, leaving some 70 militants dead. They spoke on condition of anonymity because they were not authorized to speak to the media.

Bannu is near both South and North Waziristan, two major strongholds for al-Qaida and the Taliban. South Waziristan in particular is expected to be the site of an offensive after Swat, though the military has not confirmed any plans.

Army officials could not immediately be reached to discuss the Bannu operation Wednesday.